/*
 * Copyright (C) 2008
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.test.android.opengl.glut;

import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import java.nio.ShortBuffer;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;

public class GL_Utils {

    public static void addColorf(FloatBuffer buffer, float r, float g, float b, float a) {
        buffer.put(r);
        buffer.put(g);
        buffer.put(b);
        buffer.put(a);
    }

    public static void addCoord2f(FloatBuffer buffer, float x, float y) {
        buffer.put(x);
        buffer.put(y);
    }

    public static void addIndex(ShortBuffer buffer, int index1, int index2, int index3) {
        buffer.put((short) index1);
        buffer.put((short) index2);
        buffer.put((short) index3);
    }

    public static void addVertex3f(FloatBuffer buffer, float x, float y, float z) {
        buffer.put(x);
        buffer.put(y);
        buffer.put(z);
    }

    public static FloatBuffer allocateFloatBuffer(int capacity) {
        final ByteBuffer vbb = ByteBuffer.allocateDirect(capacity);
        vbb.order(ByteOrder.nativeOrder());
        return vbb.asFloatBuffer();
    }

    public static IntBuffer allocateInttBuffer(int capacity) {
        final ByteBuffer vbb = ByteBuffer.allocateDirect(capacity);
        vbb.order(ByteOrder.nativeOrder());
        return vbb.asIntBuffer();
    }

    public static ShortBuffer allocateShortBuffer(int capacity) {
        final ByteBuffer vbb = ByteBuffer.allocateDirect(capacity);
        vbb.order(ByteOrder.nativeOrder());
        return vbb.asShortBuffer();
    }

    public static Bitmap loadBitmap(Context mContext, int id) {
        final InputStream is = mContext.getResources().openRawResource(id);
        Bitmap bitmap = null;
        try {
            bitmap = BitmapFactory.decodeStream(is);
        } finally {
            try {
                is.close();
            } catch (final IOException e) {
                // Ignore.
            }
        }
        return bitmap;
    }

    public static FloatBuffer toFloatBufferPositionZero(float[] values) {
        final ByteBuffer vbb = ByteBuffer.allocateDirect(values.length * 4);
        vbb.order(ByteOrder.nativeOrder());
        final FloatBuffer buffer = vbb.asFloatBuffer();
        buffer.put(values);
        buffer.position(0);
        return buffer;
    }

    public static ShortBuffer toShortBuffer(short[] values) {
        final ByteBuffer vbb = ByteBuffer.allocateDirect(values.length * 2);
        vbb.order(ByteOrder.nativeOrder());
        final ShortBuffer buffer = vbb.asShortBuffer();
        buffer.put(values);
        buffer.position(0);
        return buffer;
    }

}
